In the following we briefly analyze and compare voice of the two races of Black-chinned Honeyeater (Melithreptus gularis). We also try to quantify the extent of any vocal differences using the criteria proposed by Tobias et al. (2010), as a support for taxonomic review. We have made use of sound recordings available on-line from Xeno Canto (XC) and Macaulay Library (ML).
Song of both races is structurally similar, a series of repeated ringing notes, often introduced by some more raspy notes. A comparison (illustrated with multiple sonograms in the pdf version of this note): nominate and laetior.
Note shapes in song of laetior are seemingly more variable than in nominate, and on average lower-pitched. Song of nominate sounds like a ringing "rree-rree-rree..." or "rree-tup-rree-tup...". Notes of laetior sound much less ringing, duller to the ear. Measurement of the middle frequency of repeated notes gives following results:
nominate Av 2484Hz SD 92Hz
laetior Av 1987Hz SD 48Hz
This leads to a calculated Effect size of 6.77, resulting in a vocal score of 3 by application of Tobias criteria.
This note was finalized on 8th July 2016, using sound recordings available on-line at that moment. We would like to thank in particular the sound recordists who placed their recordings for this species on XC and ML: Marc Anderson, Linda Macaulay, Mark Robbins, Nick Talbot, and the staff of Macaulay Library for forwarding the recordings of David Stewart.
Tobias, J.A., Seddon, N., Spottiswoode, C.N., Pilgrim, J.D., Fishpool, L.D.C. & Collar, N.J. (2010). Quantitative criteria for species delimitation. Ibis 152(4): 724–746.
More Information: on413_black-chinned_honeyeater.pdf